SU1537841A1 - Turbine regulation system - Google Patents

Abstract

The invention solves the problem of increasing reliability with the maximum possible participation of the turbine in maintaining the network frequency. The control system contains a hydraulic regulator, a control line and an actuator, a pressure setting device, a corrector, and a safety valve. The system is equipped with a hydraulic limit line, with the corrector connecting its inputs to the control line and the limiting line, and output to the pressure setting input, the pressure setting gauge connecting its output to the limiting line, and the safety valve with its inputs connected to the control line and the limiting line, and exit - with a drain line. This allows the turbine power surges to be limited to the maximum allowed for a given current load level. 1 il.

Description

The invention relates to a power system and can be used in the regulation of steam and gas turbines.

The purpose of the invention is to increase reliability by limiting the power surges to a maximum allowable value depending on the current power value.

The drawing shows a diagram of a turbine control system.

The system contains a hydraulic speed controller 1, a hydraulic control line 2, an actuator 3, a pressure setting device 4, a corrector 5, a safety valve 6, a hydraulic limitation line 7. The power supply to the hydraulic lines is removed from the pressure manifold 8. Valve 6 is connected to a drain line 9.

The position of the spool of the hydraulic speed controller 1 is determined by the rotational speed of the turbine rotor and the setting of the load set by the operator. When changing the position of the spool of the hydraulic regulator 1, the pressure in the hydraulic line 2 of the control changes, which determines the position of the actuator 3 (servo motor with a shut-off spool) controlling the steam flow through the steam-inlets of the turbine, and consequently, the power of the turbine.

In order to limit power surges, the pressure increase in control line 2 should be limited. For this

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The control system is additionally equipped with a hydraulic limitation line 7 with adjustable pressure POGR so that a safety valve 6 is installed between the control line 2 and the limitation line 7. The safety valve 6 is made with a locking element freely placed in the housing, for example, in the form of a ball.

When performing the ratio pv a rog (pressure in the hydraulic line 2 of the control, and is the coefficient determined by the parameters of the valve 6), the drain from the control line 2 through the safety valve 6 is closed and the valve does not participate in the operation of the control system. The pressure value, with which the safety valve 6 begins to increase the drain from the control line 2, is set by the equalizer 5 depending on the current turbine power and the state of the reactor. Corrector 5 has an element of comparison and a computational unit, which can be made from known standard units both on analog electronic equipment and using integrated circuits. Corrector 5 is connected by its inputs to control line 2 and restriction line 7 and measures and compares the actual pressure drop between lines 2 and 7 Corrector 5 calculates the value of the allowable pressure drop between lines 2 and 7 and when the actual measured pressure drop differs from the calculated generates a control signal to setpoint 4, which changes the pressure in the limitation line 7 in this way and until the actual difference between the control line 7 of the limitation 7 becomes equal to the calculated one. Unit 4 is an electrical actuator.

The system works as follows. I

In static mode, the pressure in

the limitation line 7 exceeds the pressure in control line 2 by the value of the difference UP а-Р Ogr - Р, calculated by corrector 5. Peojad AP provides an instantaneous increase in power by the value of DCdlax permitted for the current actual power and given state of the reactor.

With a small and slow decrease in the speed of rotation, according to an increase in pressure Py, a new value of Rogr is calculated, which is set by setpoint 4 at the command of the equalizer 5. If the rate of decrease in rotational speed is lower than

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a possible increase in pressure P in line 7 of the limitation by command of setpoint 4, the loading of the turbine occurs without limiting the loading rate.

With a significant and rapid decrease in the rotational speed, the position of the spool of the regulator 1 changes approximately in proportion to it, which results in a decrease in the discharge from the control line 2, which leads to an increase in pressure in it. As soon as the pressure PV in line 2 of the control increases to such an extent that the Pi i AROGR inequality is violated, the safety valve 6 opens a drain from line 2 of the control, preventing further increase of pressure P.

Due to this, the magnitude of the instantaneous power surge is determined by the pressure value in the control line 2 equal to

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where rus is the pressure value at the moment

frequency changes. Simultaneously with the increase in pressure in control line 2, the actual measured pressure difference between control line 2 and limit line 7 decreases. The corrector 5 fixes the difference between the measured pressure drop and the calculated one and gives the command to setpoint 4 to reduce the drain from the limitation line 7. As the pressure in the limitation line 7 increases, the actual pressure differential increases, the drain from the control line 2 through the safety valve 6 stops and the pressure in it increases, providing a further increase in turbine power at the rate of increase in pressure in the limitation line 7 using the setting device 4.

Claims (1)

Invention Formula A turbine control system comprising a hydraulic controller connected by a control line with an actuator, an equalizer connected by its input to a line control, and the output to the pressure sensor inlet, and a safety valve connected to the control line, and the outlet to the drain line, in order to increase reliability by limiting 1537841 power surges of the maximum permissible value, depending on the current power value, the system is equipped with a limit line, to which a corrector input is connected, safety valve inlet and outlet of pressure setter.